Control means of hydraulic couplings



. M h 8, 1938. V

INVENTOR Harold 52/20/06 BY' v ATTORNEYS March 8, 1938.

H. SINCLAIR CONTROL MEANS OF HYDRAULIC COUPLINGS Filed Jan. 17, 1956 2 Sheets-Sheet 2 INVENTOR I Harold 1527i '1' BY OmWWMW ATTORNEYS g and 4 thereof. v

Patented 1938 I UNITED STATES PATENT OFFICE conflic ou- I I name Sinclair, Kensington, London, England Application January 17, 1936, Serial No. 59,520

In Great Britain January 17, 1935' The present invention relates to hydraulic couplings of the kinetic type and provided with con- 1 trol means whereby the liquid content of the .workingcircuit of the coupling can be varied while the coupling-is operating.

When such couplings are employed for certain purposes, it is desirable to be able to make relatively rapid changes in the liquid content between certain limits, that is to say, cha nges more rapidthan can conveniently be secured with the welllgnown arrangement ofscoop-tube coupling and weir control, as described in my United States- Patent No. 1,859,607

It has previously been proposed to vary the liquid content-of hydraulic power-transmitting devices bymeans of a cylinder which communicates withthe hydraulic'circuit and in which there is provided a piston, movable by a control member 'insuch a way that liquid can be transferred from the working circuit to the cylinder and vice versa. With this arrangement-when the piston is moved so as to withdraw liquid from the ,circuitgthe cylinder may become charged with reference to Figs. 1, 2

18 Claims. Y (01. 66-154) the liqu d-storage device and baclt'through the vent pi e to the coupling, gas withdrawn-from the coupling, when the liquid content of the circuitis reduced by increasing the capacity of the liquid-storage device, will be rapidly returned from that device to the coupling, so that, except during and immediately after the time when the capacity of the. device was varied, there will be a constant relationship between the position of the control member of the deviceand the quantity of liquid contained therein,. ior instance, where the device is of the piston-and-cylinder type, between the positionof the piston and the quantity of liquid contained in the cylinder. "It is not essential that the cylinder :or the like should be entirely freed from gas, since the im- 7 proved arrangement enables the degree of "frothiness in the cylinder or the like to be rapidly brought to a uniform state for any particular position of the piston or other control member, irrespective of the. extent or rapidity'of the previous displacement thereof.

The means for varying the capacity of the pis-- ton-and-cylinder or equivalent liquid-storage de- 26 with" a frothy I mixture of liquid and gas,- owing vice preferably comprise a cam which is so shaped .25

to the unavoidable entrainment of gas with. the as to compensate for irregularities in-the charworking liquid passing through the discharge 'acteristic curve of the coupling. 1 port or ports of the power transmitting device. Examples of the invention will be described as In consequence, it has not hitherto been posapplied to a hydraulic coupling employed in a '80 sible to eflec't accurately measured changes of boiler plant, to couple, for example, a draught 80' liquid content by such means. fan or a feed pump to a constant-speed motor, An object of the present invention is to prothe degree of filling of the coupling being varied vide means adapted to efiec't rapid and accurate to regulate the speed of the fan or pump in known 'changes ofyliquid content in theaworking circuit manner.

85. ,of'al hydraulic coupling. In the accompanyingdiag'rammatic drawings The characteristiccurve relating liquid content Fig.1 is a part sectional side elevation of one of a hydraulic coupling to speed of the driven embodiment of'the invention.'- element thereof is not entirely uniform in slope, Fig. 2 is asectional end elevation of a detail on and a further object of the present inventionis the line 1-2 in 1, j 1 1 40 to provide control means arranged to compensate n Fig. 3 is a part-sectional side elevation of a '40. for such irregularities.' g v Y modification of Fig. 1, and q I According to the present invention, in thecom- Fig. 4 is a graph showing the teristics .bination oil a hydraulic coupling of the kinetic "0:! the 001191 8 in Fig. 1. ,q j type with a. piston-and-cylinder, .or equivalent: like parts in the figures of the drawliquidestorage dewice of variable capacity. (such 'ings have the same. reference numerals. 45

150 per part of the cylinder or. equivalenvmember for example-ass be lows device). whichis adapt-- Q Referring to Figs. 1 and Zacomtant-speed ed to receive liquid. from and force iquid into '.electric motor llis arranged todrive a driven "the working circuit of the coupling. there is'pro machine, which in thia xamnleis a boiler feed- ..videdagasve ntcommunicatingbetweentheup-' pump ll, through a'hydraulic coupling llof the kinetic type havin'g a hnpeilerpart I3 met the liquid-storage device an'dthe interior ofkeyedtothe ll of the motor ll andavaned the hydraulic ooupling. .Providedthat-theliquid runner part II to a" drlvemzshait by transfenduct-andthe vent .pipe openinto the i a-key l1 and a nut It .dhe l lisrcoupled couplinginsuchamauner that'therefis a'cirto-the pumpshaft ll. J.-* .'"i

ll r is culation mm the coupling through the. u t to :a casing :a 'nx'ed tofthe' in liquid content of the coupling. There is thus boss ofthe runner Ii.

ing the backfof the runner, co-operates with an outer casing Ii,a1so tlxed'to the impeller, to-

form an annular chamber 22; A fixed manifold 28 surrounds the shaft It and carries ascoop tube 24 which opens within the radially outer part of the chamber 22. The scoop tube com-v municates by an outlet duct 25 formed in the,

manifold with an outlet pipe 26 leading to a 'cooler 21, while a pipe 28 connects the cooler to an inlet duct 2! in the manifold; which communie A pipe 52, branching from the scoop tube delivery pipe 2', leads to a cylinder II, the axis of which is vertical and which contains a piston 34 adapted to .be displaced by suitable control means.

The upper end of the cylinder is closed by 'a conical cover I! provided with a gas port It connected by a pipe I] to a point in the coupling where the fluid pressure is'relatively low; for example, the pipe may lead, as shown in Figs. 1

and 2, to a port "in the manifold 23, opening into the radially inner part of thescoop 'tube chamber". This pipe is substantially smaller than the liquid transfer duct 32 and it may be provided with a non-return valve 3!. e

As already mentioned the characteristic curve relating liquid content of the hydraulic coupling to speed of the driven element thereof is not entirely in slope; consequently under certain conditions oifichange of-load on the boiler, it is necessary to makela somewhat rapid reduction a tendency at such times for an excessive quantity of gas to be sucked through the liquid transfer duct 82 from the coupling into the cylinder a. with a corresponding reduction in the quantity of liquid. The excess gas-is,,howev er, rapidly returnedto the coupling through the vent port and pipe :1, being displaced byvliquid delivered by the scoop tube 2 to the liquid transfer duct 82, so that the degree of of the coupling rapidLv attains the desired 'value.

When it is desired to make a rapid increase in the liquid content of the coupling, thepiston"v 84 is merely moved in the required direction, and

the necessary quantity of liquidis returned to the circuit, without delay, under pressuredue to the force exerted onthe piston by theactuating 'lhe piston is conveniently actuated-by a'compressed-air motor, and where-asystem of autotic combustion control is employed, the comp air-motor the may be. controlled by' means including a camdevice so as to compensate for irregularitiea'in the characteristic curve oftthe andcoupiedtotbepistonflbyarodfl. sinc valve 43 actuated by a rod M, controls the mission'of air from a powersupply main st to the motor in known. manner. t e

9,110,454 j pm valv'erod u is .a differential Q the arr'angunent shown in Fig. l presed-air' motor is of the, d uble-acting type and-includes a piston working in a-cylinder Ii -tw'een the'speed of the pump device arranged to 'eflect ofacontrol medium with-a motion from the piston II.

In the example shown inl the control me- .j dium is air under a varying'pressure which is supplied to a pipe I. from an automatic master ically at i. The pressure in the pipe II is increased and decreased automatically by the mac'- ter regulator in proportionto the rise and fail oi the load on the boiler plant. rod 44 is' fixed a ilexibl diaphragm 41 forming the cover of an'air-tight chamber 48 communieating with the control air pipe 4'6, "Hie-piston rod extends through a bearing in the bottom of a tensionvspring 80 the r and of which is adapted to be displaced, in response'to move mentfoi' the pistons 34 and 40, through the agency of a bell-crank lever ti mounted-ona ii'xed pivot 52. One arm of theJbeIl-crank lever is pivotally regulate of known type. indicated diagrammab, V

To the 'valve 49 oi the chamber 48 and is secured toone eti'd connected to the spring ".while the other arm .ends in a cam follower 53, which is engaged in a ton rod 42;

Fig. 1 shows nism in an equilibrium condition: If the control air pressure in the pipe rises; for example. the upwardior'ce acting onthe' diaphragm l1 exceeds the downward iorce exerted by the spring I so thatthe valv'arod it rises, permitting air cam groove 54 formed in a plate iixed torthe pi s the servo-motor control fromthe power main 4! to iiowto the under,

side of the piston 40. The pistons ll and it rise in consequence and the cam it rocks therbelicrank lever. anti-clockwise, so as to increase the tension of thespring 50 and-draw the-valve rod 44 downward, so that the valve closes as -soon as the pistons haverisen through a distance appropriate to the change'inbontrol air. pressure. In a similar way, if the control air pressure falls. the valve rod 4! is drawn downward by the spring 3., with the result that the pistons are causedto descend. The cam l4 nowmove's'the bellcrank lever 5i clockwise'reducing the tension of the spring. 1

In Fig. 4 the curve A indicates thezvariation of the speed of the pump ll (Fig. l) with the liquid v content of the hydraulic coupling the speed being plotted as ordinate and thevalues being ex,-

pressed as percentages of their maximum workthe range ing limits; It will be seen that over of filling from about 50 to '70 percent the slope;

not the speed curveis less steep than elsewhere.

Over the part of the range otemptying and filling-of the hydraulic coupling where-s relatively-large variation in liquid content has tobe made' for a given change in speed o( the feed' I pump i'-i ,it-is necessary for .the'pistons-tl and f to travel arelativeiy long distanceffor a given vai'istionfloi theZcontroLair comequently the part ofthe cam groove 1 that engages the cam follower It over this particular ran'ge of travel of'the pistons has theremainderr intlm example ahown in 1mg. ,1 the part of thecamgroove betweenthe points '4' and H" is or reduced slope. It'll] be obvious that the same eilect be-attained by plaoing the compensating cam mechanism 3 elsewhere, for ln a theair'pressure-inthepipettf'fl .curve'ninl 'lgJ indicatssthei-eiationshipbs- (asl ordim te') and thecontrolair'pressure; Itwillbeseenthatthe' val' ationin-stoevaels cam groove "has the eilect of compensating for the irregularity in 4.'In' combination, a hydraulic coupling of the speed liquid-content relationship so as to make the speed control-air-pressure S relationship substantially linear.

The arrangement shown inFig. lniay be mod-e,

maintain a fluid pressure of about 7 lb. per sq.

in. in the outlet pipe, in the liquid-transfer pipe 32 and in the cylinder'33a above the piston a. The. lower end of the cylinder 33a serves 'as the compressed-air motor, the admission and exhaust of air being controlled by a valve In actuated by a rod a. The valve rod 0 is controlled by a difierential pressure device similarpin principle "to that shown in Fig. 1 and comprising a diaphragm 41 influenced by the control 'air pressure from pipe 46, a tension spring 50a connected to the kinetic type having a fluid outlet port, a fluid inlet port, and means utilizing the energy of motion of liquid within said coupling for establishing a, diflference of fluid pressure between said ports, a hydraulic circuit connecting said ports together, said circuit including a stationary liq-- uid-storage, chamber having adisplaceable wall and a duct leading from the top of said chamber to said inlet port, and control means, for displacing said wall to vary the capacity of said chamber. I 5.. In combination, a Hydraulic'coupling having a working circuit for coupling liquid, a stationary liquid-storage chamber, control means for varying the capacity of said chamber, a liquid-transfer duct between said chamber and said circuit, a

gas port debouching from the top of said chamher, and a duct communicating between said gas port and said circuit, said duct including a nonreturn valve arranged to prevent flow of fluid through said ber. s

6. In combination, ahydraulic coupling of the kinetic type having a liquid transfer'port,

means utilizing the energy 01' motion of liquid 2. bell-cranklever Fla, and a cam 54a co-operating with a cam'follower 53a and mounted on the piston rodfla.

. 'When the controlair pressure falls and permits air under the piston 34a to be exhausted,

the pressure existing in the liquid transfer duct 3! causes the piston to fall so that liquid is transferred from the coupling to the upper end of the said circuit.

2. In combination, a hydraulic coupling of the plac'ed is regulated by the differential pressure within ,the coupling tor forcing liquid o'ut oi said.

port, and a fluid inlet port opening. within said" coupling at a point adjacent to the axisjof rotation thereof, a stationary liquid-storage chamber,'control means for varying the capacity of last mentioned duct 'to said chamsaid chamber, a duct communicating between I said chamber and said liquid transter port. and a ductdebouching from the top of said chamber and leading to ,said' fluid inlet port.

- 7. In combination, a hydraulic coupling of the kinetic type-having a liquid'inl'et'port and a liquid outlet port, an auxiliaryliquid circuit con-.

nected between said ports, means for maintain- ;ing a liquid circulatiodthropgh said auxiliary control device, in accordance with the extent of the change in control air pressure.

I claim:

circuit, a stationary liquid storage chamber, a duct branching from, said auxiliary. circuit, andopening into said chamber, control means for 1. In combination, a hydraulic coupling having a working circuit for coupling liquid, a stationary liquid-storage chamber, control means for vary-= ing the'capacity of -saidchamber, a liquid-transfer duct between said. chamber and said circuit,

hood or the top of said chamber and leading to kineticvtype having a working circuit, a stationary varying the capacity of'said chamber, and a vent duct having one-end debouching from the upper part ofsaid chamber and the other end comand a gas vent'debouching from the neighbortrol means for varying the capacity of said chamber, whereby said chamber can force liquid into and withdraw liquid from said circuit, and a gas vent opening outoi. the top of said chamber and leading to ,the interioroi said coupling. 1

tatable relative to said scoop member, an outlet duct for discharging liquid engaged by said scoop member, a stationary liquid-storage chamber,

control means for-varying the capacity of said chamber, said chamber communicating with said outletduct; and a gas vent opening out of the top of said ehamber'and leadingto the interior of said coupling. I

cylinder having'its axis out of the horizontal and its upper end closed, a piston -co,-oper ating with said cylinder, control means for actuating said piston, a liquid transfer duct leading iromsaid outlet port and opening into said cylinder above saidpiston, anda gas vent debouching from the top ,0! said cyl nder and leading to said inlet port.

9., In combination, a hydraulic coupling 0! the kinetic type having aiiquid outlet port a fluid inlet port,and means for discharging liquid from the interior of said coupling-through saidoutlet port, a cylinder having its axis substantially vertical and its upper end closed by a dished mem-' opening intosaidcflinde'r above said piston, and

agas ventfdebouchingirom the top oi'said fdished member and leading to said-inlet port.-

10. In combination, ahydraulic coupling com prising a working circuit, said coupling having a liquid-content-runner-speed characteristic of irregular slope,.a reservoir communicating with a servo-motor ior actuating said piston, control means tor-starting and stopping said servo-motor,v

"ma circuit, and wit-m1" means for vsryins the efl'ecti'vecapacit'y of said reservoir and -thereby varying liquid content of said circuit, said control means comprising 'a cam so shaped as to compensate for at least of the irregularity of said characteristic.

-. 11..1n combination, a hydraulic mm or the kinetic type comprising a working circuit, said coupling having a liquidcontent runner-speed characteristic of irregular slope, a liquid-storage chamber communicating with ,said'circuit, means for varying the capacity of said chamber and cult, a servo-motor i'or actuating said means, and" thereby transferring liquid to and from" said cir.-

a cam device operatively connected with said servo-motor and said capacity-varying means,

' i said cam device being so shaped asto compensate f 0 i at-Ileast part of the'irregularity oi said characterist'ic Y 12; In combination, a hydraulic coupling of the kinetic type comprising a working circuit, said 3 coupling having a liquidcontent runner-speed .charactris'tic or irregular slope, a cylinder ccm- '13; In, combination, a

the kinetic comprising a working. circuit,

municating with said circuit, IADIStOD slidable in said cylinder to transfer liquid to said circuit,

said contrormeans including so shaped as to compensate for at least partroi the-irregularity oi',ssid characteristic, a pressure-responsive device for actuating said control means, and a follow-up connection between said piston and said control meins.

said coupling having a liquid-content runner:

'rspeed'charaoteristic oi irregular slope, .a cylinder communicatingwith said circuit, a piston slid able in said cylinder to transfer liquid to said circuit, a fluid-pressure servo-motor ion actuate.

ing said piston, a cohtrol valveior said-servo-' motor, control means for displacing said valve,-'

' and a. follow-up connection between said valve and said piston, said connection including a camsoshapedastocompensateiorat leastpart oi the irregularity of said 14. In combination, a hydraulic coupling of netlc' ypehaving-a liquid-content runnerspeed characteristic'oi irregular slope, said couslins be s pr id w a d. ran ferport, a fluid inlet port,'and means responsive to the motion oi liquid within the coupling for main- .taining a fluid pressure diflerence between said' ports, a stationary cylinder, aduct communicat- 65 ing'between said cylinder'and said liquid transier-po'r't, a gas vent debo'uching from the top-oisaid cylinder and leading to said inletportra piston siidably flttedfl in vsaid cylindera servomotor operatively connected with piston,

90 control means iorfsta'rting and 'stoppingsaid so shaped as to compensate to: the umm nw seryoemotor, said control means including a cam 's,11o,sos

said cylinderand leading OI-R1111! port, a

piston slidably fltted'in said cylinder, a servomotor operatively connected with said isten. control means ior starting and stoppim said servo-motor,-s pressure-responsive device operatively connected with said control means and a return-motion connection which is coupledbetween 'said'ccntrol means and said piston and whichinclude'sacamsoshapedastocompensate' tor at-le'astpart'oitheirregularity ofsaidcharacteristic.

. i6. In combination, a hydraulic couplim havingafluidinletport,aliquidoutletport,and means utilising the energy oi motion or liquid within the coupling ior establishing a diflerence oi fluid pressure between said ports, a hydraulic circuit connecting said ports together; said cir- 4 cult insluding' a stationary liquid storage cylinder andaductleadingtromthetopoisaidcylmder to said inlet port, a piston movablein said cylin- 1 der tor iorcingliquid into and withdrawing liqhydraulic'coupling oi uid from said coupling, a servo-motor ioractuating said pistonlacontrol member for starting and stoppingvsaid servo-motor, ands return- -mction connection between said said control member. v 4

17. In combination ahydraulic coupling Inving a workingcir'cuit ior coupling liquid, a oyiinder, a piston movable in said cylinder and; torming therewith a liquid-storage chamber '01"!!!- able-capacity, a humid-transfer duct between said chamber and said circuit, a gas vent said chamber and said circuit, and control means for'movlngsaidpistm.

1a. Infco'mbination, a hydraulic oi thekin'etictypehavingaw'orking circuit iorcoupling'liquid; a liquid outlet port, a fluidinlet port and meanaiol ceedingthepressureatsaidinletpo'rt,'aliquid I liquid irorn'sald cit. cult through said outlet port at a pressureexstorage chamber. control means operable (or varying the eflective capacity-oi said chamber.

iromsaidcircuittosaidchamber,-anda'duet communicating with said chamber and so poltinned/as, to receive gas dischargedwithlimid mm said circuit, inlet port.

said'ductleadingto said fluid so 

